The inverse is true, though - climate skeptics are oftentimes paid by the (very rich) petrol lobby to espouse skepticism. It's not an asinine attack, just an insecure one from an audience that also overwhelmingly accepts money in exchange for astroturfing opinions. The clear fallacy in their polemic being that ad-hominem attacks aren't addressing the point people care about. It's a distraction from global warming, which is the petrol lobby's end goal.

Yudkowsky's rhetoric is sabotaged by his ridiculous forecasts that present zero supporting evidence of his claims. It's the same broken shtick as Cory Doctorow or Vitalik Buterin - grandiose observations that resemble fiction more than reality. He can scare people, if he demonstrates the causal proof that any of his claims are even possible. Instead he uses this detachment to create nonexistent boogeymen for his foreign policy commentary that would make Tom Clancy blush.